1. Field of the Invention
This invention relates to the field of foams and more specifically to the field of polyurethane and polyisocyanurate foams.
2. Description of the Related Art
Surfboard and preboard foam have conventionally been manufactured using toluene diisocyanate (TDI) and TDI prepolymers as the isocyanate. Such conventional manufacturing has resulted in worker exposure and environmental issues, which have primarily caused this production to cease.
In addition to safety concerns, polymeric methylene diphenyl diisocyanates such as Rubinate 1850 typically give a tan (e.g., dark brown) foam, which may be unacceptable to surfboard manufacturers. To overcome such typically unwanted colors, the use of other isocyanates has been developed. For instance, other specialty isocyanates (e.g., toluene diisocyanate or aliphatic isocyanates such as hexamethylene diiscyanate or isophorone diisocyanate) may be used to make a white, color-stable foam. Drawbacks to such other isocyanates include that the material may be toxic and expensive. Further drawbacks include that the reaction is extremely slow to form polyurethane and polyisocyanurate foam.
There is a need, therefore, for a method to produce a polyurethane foam in a safe and environmentally acceptable manner. There is also a need for a less expensive method to produce a white, color stable foam.